CA 19-9. Hi. Have you had pancreatic adenocarcinoma? If so, I can just about guarantee you your oncologist has ordered a CA 19-9 (or multiple values, following longitudinally with treatment). If you haven't had pancreatic adenoCA, I'm not aware of CA 19-9 being used as a screening tool. In any event, ignorance of facts is never helpful. Go ahead and ask. Good luck!